Subject: [PATCH v2 04/15] spi: Replace open coded spi_controller_xfer_timeout()

From: Andy Shevchenko <[email-masked]>
Date: Mon, 10 Jul 2023 18:49:21 +0300

Since the new spi_controller_xfer_timeout() helper appeared,
we may replace open coded variant in spi_transfer_wait().

Signed-off-by: Andy Shevchenko <[email-masked]>
---
 drivers/spi/spi.c       | 25 ++-----------------------
 include/linux/spi/spi.h |  6 +++++-
 2 files changed, 7 insertions(+), 24 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 125dea8fae00..c99ee4164f11 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1342,8 +1342,7 @@ static int spi_transfer_wait(struct spi_controller *ctlr,
 {
 	struct spi_statistics __percpu *statm = ctlr->pcpu_statistics;
 	struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics;
-	u32 speed_hz = xfer->speed_hz;
-	unsigned long long ms;
+	unsigned long ms;
 
 	if (spi_controller_is_slave(ctlr)) {
 		if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
@@ -1351,29 +1350,9 @@ static int spi_transfer_wait(struct spi_controller *ctlr,
 			return -EINTR;
 		}
 	} else {
-		if (!speed_hz)
-			speed_hz = 100000;
-
-		/*
-		 * For each byte we wait for 8 cycles of the SPI clock.
-		 * Since speed is defined in Hz and we want milliseconds,
-		 * use respective multiplier, but before the division,
-		 * otherwise we may get 0 for short transfers.
-		 */
-		ms = 8LL * MSEC_PER_SEC * xfer->len;
-		do_div(ms, speed_hz);
-
-		/*
-		 * Increase it twice and add 200 ms tolerance, use
-		 * predefined maximum in case of overflow.
-		 */
-		ms += ms + 200;
-		if (ms > UINT_MAX)
-			ms = UINT_MAX;
-
+		ms = spi_controller_xfer_timeout(ctlr, xfer);
 		ms = wait_for_completion_timeout(&ctlr->xfer_completion,
 						 msecs_to_jiffies(ms));
-
 		if (ms == 0) {
 			SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
 			SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 32c94eae8926..0ce1cb18a076 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -1270,12 +1270,16 @@ static inline bool spi_is_bpw_supported(struct spi_device *spi, u32 bpw)
  * that it would take on a single data line and take twice this amount of time
  * with a minimum of 500ms to avoid false positives on loaded systems.
  *
+ * Assume speed to be 100 kHz if it's not defined at the time of invocation.
+ *
  * Returns: Transfer timeout value in milliseconds.
  */
 static inline unsigned int spi_controller_xfer_timeout(struct spi_controller *ctlr,
 						       struct spi_transfer *xfer)
 {
-	return max(xfer->len * 8 * 2 / (xfer->speed_hz / 1000), 500U);
+	u32 speed_hz = xfer->speed_hz ?: 100000;
+
+	return max(xfer->len * 8 * 2 / (speed_hz / 1000), 500U);
 }
 
 /*---------------------------------------------------------------------------*/
-- 
2.40.0.1.gaa8946217a0b